MM-55966 - Update ArrayFromJSON to use LimitedReader (#25510)

* update ArrayFromJSON to use LimitedReader

* update for bad merge

* fix lint errors

* update test code

* update unit tests

* update unit tests

* fix unit tests

* use consts, other cleanup

* add non sorting duplicate check

* set config to default value, then config setting if available

* fix lint errors

* fixes and debugs

* fix log test

* remove setting from Client, add unlimited Parser to client

* a couple more fixes

* another fix

* rename some variables

* remove superflous call

* check for valid MaximumPayloadSize

* update language file

* fix for e2e-tests

* update util function to return error

* lint fix

* update config property name to include unit

* fix for unit test

* add new config to telemetry

* call function to create LimitedReader

* Deprecate old function, use new function name

* return new AppError on failed parse

* return new AppError on failed parse

* return new AppError on failed parse

* add constant for i18n valid constants

* Update server/public/model/utils_test.go

Co-authored-by: Miguel de la Cruz <mgdelacroix@gmail.com>

* Apply suggestions from code review

Co-authored-by: Miguel de la Cruz <mgdelacroix@gmail.com>

* update error variable, remove unnecessary check

* Update function names

* fix errors from merge

* update unit test to create unique ids

---------

Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: Miguel de la Cruz <mgdelacroix@gmail.com>

server/channels/api4/user.go

@@ -623,9 +623,11 @@ func getFilteredUsersStats(c *Context, w http.ResponseWriter, r *http.Request) {
 }
 
 func getUsersByGroupChannelIds(c *Context, w http.ResponseWriter, r *http.Request) {
-	channelIds := model.ArrayFromJSON(r.Body)
-
-	if len(channelIds) == 0 {
+	channelIds, err := model.SortedArrayFromJSON(r.Body, *c.App.Config().ServiceSettings.MaximumPayloadSizeBytes)
+	if err != nil || len(channelIds) == 0 {
+		c.Err = model.NewAppError("getUsersByGroupChannelIds", model.PayloadParseError, nil, "", http.StatusBadRequest).Wrap(err)
+		return
+	} else if len(channelIds) == 0 {
 		c.SetInvalidParam("channel_ids")
 		return
 	}
@@ -636,7 +638,7 @@ func getUsersByGroupChannelIds(c *Context, w http.ResponseWriter, r *http.Reques
 		return
 	}
 
-	err := json.NewEncoder(w).Encode(usersByChannelId)
+	err = json.NewEncoder(w).Encode(usersByChannelId)
 	if err != nil {
 		c.Logger.Warn("Error writing response", mlog.Err(err))
 	}
@@ -953,17 +955,15 @@ func requireGroupAccess(c *web.Context, groupID string) *model.AppError {
 }
 
 func getUsersByIds(c *Context, w http.ResponseWriter, r *http.Request) {
-	var userIDs []string
-	err := json.NewDecoder(r.Body).Decode(&userIDs)
-	if err != nil || len(userIDs) == 0 {
-		c.SetInvalidParamWithErr("user_ids", err)
+	userIDs, err := model.SortedArrayFromJSON(r.Body, *c.App.Config().ServiceSettings.MaximumPayloadSizeBytes)
+	if err != nil {
+		c.Err = model.NewAppError("getUsersByIds", model.PayloadParseError, nil, "", http.StatusBadRequest).Wrap(err)
+		return
+	} else if len(userIDs) == 0 {
+		c.SetInvalidParam("user_ids")
 		return
 	}
 
-	// we remove the duplicate IDs as it can bring a significant load to the
-	// database.
-	userIDs = model.RemoveDuplicateStrings(userIDs)
-
 	sinceString := r.URL.Query().Get("since")
 
 	options := &store.UserGetByIdsOpts{
@@ -1002,10 +1002,12 @@ func getUsersByIds(c *Context, w http.ResponseWriter, r *http.Request) {
 }
 
 func getUsersByNames(c *Context, w http.ResponseWriter, r *http.Request) {
-	var usernames []string
-	err := json.NewDecoder(r.Body).Decode(&usernames)
-	if err != nil || len(usernames) == 0 {
-		c.SetInvalidParamWithErr("usernames", err)
+	usernames, err := model.SortedArrayFromJSON(r.Body, *c.App.Config().ServiceSettings.MaximumPayloadSizeBytes)
+	if err != nil {
+		c.Err = model.NewAppError("getUsersByNames", model.PayloadParseError, nil, "", http.StatusBadRequest).Wrap(err)
+		return
+	} else if len(usernames) == 0 {
+		c.SetInvalidParam("usernames")
 		return
 	}